A laparoscopic surgery is applied more and more widely. In order to avoid iatrogenic infection, the consumption of a disposable trocar used in the laparoscopic surgery is increasingly greater. The trend of simplifying the structure, reducing the cost, improving the performance on the basis of ensuring using performance has already become an improvement direction of the trocar.
In the prior art, a sealing structure of the trocar is formed by a radial sealing ring and a check valve. A common check valve, namely, an axial sealing apparatus has two types. One type is a spring pressed structure, forming sealing by a spring leaf pushing a flapper to oppress a silica gel sealing ring. The check valve is formed by the spring leaf, the flapper and the silica gel sealing ring, the spring leaf and the flapper are generally made of stainless steel, the form of the sealing ring is usually used in a metal-made reusable trocar, and the trocar is expensive and has a heavy weight. In recent years, in order to adapt to the development requirement of the disposable trocar, a funnel-shaped silica gel sealing ring is developed. The funnel-shaped silica gel sealing ring has a straight through notch provided at the bottom of the funnel, and achieves the sealing effect by means of the contractility of the silica gel and the pressure formed by carbon dioxide pneumoperitoneum during use. The funnel-shaped silica gel sealing ring is generally widely applied in the disposable trocar. The radial sealing ring generally adopts a funnel-shaped structure with a central hole and the sealing ring easily leaks when a surgical instrument shakes, having a poor dynamic sealing effect. Additionally, when a 10 mm or 12 mm surgical instrument is inserted in a medical silica gel sealing ring with the diameter being 4 mm, the resistance of the surgical instrument in reciprocating motion is also large, which brings inconvenience to a surgical operation of a surgeon.
Additionally, surgical instruments have heads in different shapes. Particularly, a surgical instrument, such as a titanium clamp, has a V-shaped head splayed when being delivered to the abdominal cavity through the trocar, and generally cannot pass through the funnel-shaped silica gel sealing ring in the prior art. Another defect of the V-shaped funnel-shaped silica gel sealing ring is that a surgical instrument whose head has a groove or raised steps, such as a harmonic scalpel, is easy to get stuck when the surgical instrument is removed, so the motion is not smooth.
Therefore, the radial sealing apparatus of the existing trocar needs to be improved, so as to achieve the purpose of not only using a 10 mm instrument on a trocar whose diameter is 10 mm, but also using surgical instruments with diameters between 5 mm and 10 mm; and not only using a 12 mm instrument on a trocar whose diameter is 12 mm, but also using surgical instruments with diameters between 5 mm and 12 mm, thereby being general. Meanwhile, the radial sealing apparatus of the improved trocar can be adapted to various surgical instruments in different shapes, thereby facilitating insertion and removal of the instrument, with low resistance and smooth motion. Evidently, the sealing apparatus and the trocar in the prior art cannot satisfy the requirements, thus requiring improvement.